Fig. 2.

A CFR (Case-Fatality Ratio) as shown by outbreaks by year. The calculations and data shown have been adjusted for “noise” especially involving samples with the number of cases in the outbreaks that are too small to be reliable. Regression analysis (p < 0.01, F = 44.1, r² = 0.81) shows correlation between the CFR and year of infection. One-Way ANOVA analysis based on dividing three groups, 1998–9, 2001–6, and 2008–12, has yielded a statistically significant result (One-Way ANOVA: F = 49, p < 0.01). Average CFRs (~40% in 1998–9, ~75% in 2001–5, and ~85% in 2007–12).